Identification and telemetry system

Abstract

The present invention relates to a system for automated identification of articles such as baggage or carrier cargo wherein an electronic sub system called an interrogator including a transmitter and receiver extracts by electromagnetic means useful information from an electronically coded label attached to such items as they are processed through the sorting operations at an airport or node of an article handling organization.

We claim: 
     
       1. An identification and telemetry system comprising: a transmitter for generating an interrogation signal and a receiver for detecting and decoding a reply signal;   an interrogation field creation means for generating, within a scanned region, from said interrogation signal, an interrogation electromagnetic field through which an object possessing a code responding label may pass;   an auxiliary illumination system for generating within said scanned region an auxiliary illumination field;   a code responding label including a receiving antenna for receiving from the interrogation electromagnetic field a label interrogation signal, and sensing means for receiving from the auxiliary illumination field an auxiliary illumination signal, microcircuit means for generating from information stored within the label and from said auxiliary signal a label reply signal, and means within the label for generating from the label reply signal a label reply electromagnetic field; and   a receiver antenna connected to said receiver for receiving from the label reply electromagnetic field a system reply signal;   said label reply signal containing information indicative of the auxiliary illumination signal detected by the label.   
     
     
       2. An identification and telemetry system as claimed in claim 1 wherein the auxiliary illumination field is well collimated as to spatial extent. 
     
     
       3. An identification and telemetry system as claimed in claim 2 wherein the auxiliary illumination field comprises an electromagnetic field within one of the ultra-violet, visible, infra-red and microwave regions. 
     
     
       4. An identification and telemetry system as claimed in claim 1 wherein said sensing means uses a photoconductive medium. 
     
     
       5. An identification and telemetry system as claimed in claim 1 wherein said sensing means is disposed within the microcircuit means. 
     
     
       6. An identification and telemetry system as claimed in claim 1 wherein the label reply signal contains information indicative of whether the label has or has not passed through the auxiliary illumination field. 
     
     
       7. An identification and telemetry system as claimed in claim 1 wherein the label reply signal is enabled only when said auxiliary illumination signal is detected by the label. 
     
     
       8. An identification and telemetry system as claimed in claim 1 wherein the label reply signal is disabled when said auxiliary illumination signal is detected by the label. 
     
     
       9. An identification and telemetry system as claimed in claim 1 wherein modification of said label reply signal produced as a result of the auxiliary illumination signal is used to determine relative positions of labels which are simultaneously present within the scanned region. 
     
     
       10. An identification and telemetry system as claimed in claim 1 wherein the label reply information contains a label memory data field and a label reply tag field, said tag field containing information describing the auxiliary illumination signal detected by the label. 
     
     
       11. An identification and telemetry system as claimed in claim 1 wherein the label reply signal contains information indicative of the strength of the auxiliary illumination field. 
     
     
       12. An identification and telemetry system as claimed in claim 10 wherein the label memory data field contains a cyclic redundancy check and the label reply tag field contains at least one parity check. 
     
     
       13. An identification and telemetry system as claimed in claim 1 wherein each interrogation antenna comprises a short range magnetic dipole mounted so as to be able to remain in close contact with labelled objects as the objects move through the scanned region.